Sliding switch construction



Nov. 17, 1964 p, J. VAN DEN BERK 3,

SLIDING SWITCH CONSTRUCTION Filed April 25. 1961 uswlllllllllullul llll n FIGJ FIGB

FIG.4

' INVENTOR -PETRUS JLVAN new BERK.

1?. AGENT United States Patent 3,157,751 SLIDING SWITCH CUNSTRUCTIGN Petrus Johannes van den Berk, Eminasingel, Eindhoven,

Netherlands, assignor to North American Phiiips Company, Inc, New York, N.Y., a corporation of Delaware Filed Apr. 25, 1961, Ser. No. 105,430 Claims priority, application Netherlands lune 23, 1%0 7 Claims. (Cl. Hill-l6) The invention relates to a sliding switch of small dimensions comprising a longitudinally displaceable strip member, which is provided at least on one side with two longitudinally parallel rows of contacts arranged on the surface of the strip and an insulating frame within which said strip is slideable relative to strip-shaped, stationary contact springs approximately parallel to the surface of the contact strip. By fastening the contact springs individually to one of two fillets of the frame, each of which is arranged adjacent one of the two rows of sliding contacts, provides the advantage that the resilient parts of all contact springs can have the same length and the exerted contact pressure may have the same value with all springs, which is of great importance with regard to a smooth travel of the slide and the requirement of a small driving force.

The known device has, however, a disadvantage in that the connecting tags formed by the ends of the contact springs projecting sideways beyond the frame are located along the two longitudinal edges of the frame on each side thereof. In the preferred mounting of the switch on a, e.g., horizontal surface of a chassis, longitudinally parallel and laterally orthogonal thereto, so that the switch occupies a minimum space in the chassis, the connecting tags are located along the lower edge and the upper edge of the frame. This renders the switch less suitable for mounting on a chassis plate with surface wiring (for example printed wiring), in which case the soldering tags are directly soldered in the chassis plate and even with the conventional wiring it is a disad vantage.

In accordance with the invention this disadvantage is obviated in that at the side of each of the contact springs secured in one of the two fillets provision is made of at least one narrow, metal strip arranged parallel to the spring and integral herewith, connected with the spring assembly near the spring-supporting fillet, and secured in the proximity of the free end of the spring in the other fillet for forming a pair of soldering tag in a single plane. The connecting tags of the contact springs may all be arranged in this case along the same edgein the case of surface wiring along the lower edge-of the switch, whereas a number of the contact springs or, if desired, all of them, may have a connecting point along both edges. The stationary contact springs are preferably arranged to co-operate with the row of sliding contacts remote from the fastening ends of the springs. In this case the connections formed by the narrow metal strips are as short as possible and the height of the switch may be minimized.

The invention will be described more fully with reference to the accompanying drawing, in which FIG. 1 shows a presently preferred embodiment of the invention in a side elevational view partly broken away.

FIG. 2 shows the sliding switch of FIG. 1 in an end view partly in a vertical section.

FIG. 3 shows the switch in a top view and PEG. 4 shows the contact slide of the switch in a separate view. The sliding switch shown comprises a plurality of con ductor on contact plates 1, which are surrounded by a frame 3 of insulating compressed material, for example 3,l57,75l Patented Nov. 17, 1964 polystyrene, within which frame a stripshaped slide 5 of insulating material, for example hard paper, is displaceable in the longitudinal direction of the strip (see FIGS. 2 to 4; in FIG. 1 the slide 5 is shown only diagrammatically for the sake of clarity). Conductor plates 1 are secured alternately in two fillets 7 and 9, arranged along the longitudinal edges of the sliding contact strip 5, at ABCDE, the fillets constitute the main part of the insulating frame 3. Each conductor plate has a contact spring la extending parallel to the surface X and Y of the strip 5 and in the present case at right angles to the longitudinal direction and parallel to the direction of width of the contact strip 5 and co-operate with two spaced rows of contact plates 11 and 13 arranged on the surface of the strip 5 (FIG. 4). The contacts 11 and 13 may be provided on the strip surface for example by means of a suitable printing process. At the free ends of the contact springs 1a are substantially circular embossed elevations 15, which engage (see FIG. 2) with a certain amount of resilient pressure, the contact plates 11 and 13 on the slide. The conductor plates 1 project at the other end beyond the fillets 7 and 9 outside the frame 3 and constitute in a conventional manner soldering tags it? and 25 and i9 and 27. The soldering tags 17 and 27, which are formed on the plates 1 in the lower llet 9 are narrow and are adapted to be inserted into apertures of a horizontal chassis plate with surface wiring and to be soldered therein, whereas the soldering tags 19 and 25, which are formed on the plates in the upper fillet 7 are provided with apertures 21 and are suitable for the connection of wires.

FIG. 1 shows that at the side of each of the contact plates 1 provision is made of a narrow metal strip 23 parallel thereto and integral therewith, which strip is connected with its associated spring 1a near the fillet supporting the spring, while the other end of a strip is secured in the opposite fillet (in the same plane) and constitutes a soldering tag beyond its adjacent fillet. At the central plate (located at position C FIG. 1), supported by the lower fillet 9 (for the sake of clarity the portion of the frame 3 located in front of this plate is broken away), the strip 23 is connected near the fillet 9 with the spring In, as is shown in FIG. 1, while the free end of the strip 23, which has a locally widened part, is secured in the fillet 7 and projects beyond this fillet by a portion constituting a soldering tag 25.

Particularly important is the strip 23 for the two contact plates 1, located one on each side of the central contact spring at position C of FIG. 1 and both secured in the upper fillet 7. The metal strips 23 for these contacts constitute a short, electrical connection with the lower side of the switch and the narrow soldering tags 27, formed at the free ends of the strips 23 secured in the opposite or lower fillet 9. Thus the contact plates 1 secured in the upper fillet 7, are also connected directly, i.e., without Wires to lower fillet 9 on a chassis plate with printed wiring. It is therefore essential that at least the contact plates 1, secured in one of the fillets, in this case in the upper fillet 7, should be provided with a connect ing strip 23 along the side of spring in so that all plates and associated springs can be connected along one longitudinal edge of the switch. The arrangement described is advantageous not only for printed wiring but also for conventional wiring, since it permits of connecting at least a few contacts at will either on one side or on the other side of the switch; it all contact plates are provided, i.e., the central as well as its adjacent springs in the manner shown with a longitudinal metal strip 23, the said possibility is given for all contact springs.

Each of the stationary contact springs in co-operates preferably in the manner illustrated in FIGS. 1 and 2 with the row of contacts on the slide remote from the connecting point of the spring 10, that is the contact plates secured in the fillet 9 cooperate with the contacts 11 and the spring contacts in secured in the fillet '7 with the contacts 13. it is evident from FIGS. 1 and 2 that the connection formed by the metal strips 23 may be as short as possible consistent with adequate flexibility of the contact springs to and that the height of the whole switch may be considerably reduced.

The two horizontal fillets 7 and 9 of the frame 3, of insulating, sprayed or compressed material, are connected by means of vertical rod-shaped parts 29 of the frame 3 extending along or over the narrow metal strips 231. The two fillets 7 and 9 are thus united in a rigid unit or frame, while the metal strips 23 are protected to some extent from outward mechanical forces, which might cause one or more of the metal strips 23 to bend down, which would render the switch unserviccable. At the area of the contact springs to the frame 3 remains open, which is eificient with regard to economizing insulating material and to the possibility of readapting by bending the springs 1a after the frame 3 has been sprayed. If, as is shown in FIG. 3, rectangular apertures 31 are provided between the fillets '7 and 9, the springs are exposed and their tension can be controlled. It is thus, moreover, more easily to withdraw the plates 1 one after the other out of the frame, which is required for replacing a defective plate or switch, since it is very difficult to loosen all soldering tags 17 at the same time. Owing to the metal strips 23 all contact plates and springsincluding also those secured in the lower fillet 9-can be withdrawn from the switch 3 in an upward direction, the contact springs can be withdrawn without any difiiculty one after the other after the soldering tags 17 and 27 have been loosened and finally to remove the whole switch.

Although in the embodiment shown in FIG. 1 only one connecting strip 23 is provided at the side of each contact plate, two of these strips may, of course, be provided one on each side of the contact plates. sible to provide a row of contact plates 1 on only one side or (see FIG. 3) on both sides of the slide 5; in the latter case the slide would be provided on both sides with contacts 11 and 13.

it is not necessary for the contact plates ll to be arranged accurately at right angles to the longitudinal direction and accurately parallel to the direction of width of the slide 5 in the fillets 7 and 9; if desired, the plates may be arranged at an angle of about 45 to the longitudinal direction (approximately) parallel to the surface of the slide. The switch is then longer but less high, which may be desirable for matching the dimensions of further parts of the apparatus of which the switch forms part.

What I claim is:

1. In a sliding switch the combination comprising an open frame member having spaced parallel longitudinal fillet means defining a plurality of first openings in said frame in a first plane normal to the longitudinal axis of said switch, a plurality of spaced parallel rod means interconnecting and supporting said fillets and defining a plurality of second openings in said frame normal to the longitudinal axis of said switch and the said first openings, a central longitudinal passage through said frame member, a sliding member in said passage, said sliding member having a plurality of contact pieces in spaced parallel rows adjacent the longitudinal edges of said sliding member, and a plurality of spring, contacts secured in said frame, said spring contacts comprising a conduc tive plate having a resilient tongue portion and soldering tags at the longitudinal extremities thereof projecting beyond said fillets of said frame, said spring contacts being secured in said frame for access thereto through at least one of said openings to adjust thetension of said tongue portion.

It is furthermore pos- 2. An article of manufacture comprising a spring contact for a sliding switch, said contact comprising a substantially rectilinear plate of electrical conducting material, said plate having soldering tags at each end thereof, a leaf spring contact portion struck from one side of said plate between said tags and bent out of the plane of said plate, the other side of said plate adjacent said spring contact defining a strip portion interconnecting said tags.

3. A sliding switch comprising an elongated frame member having a central passage and a first and second plurality of apertures therein defined by longitudinal fillets and transverse rod members supporting said fillets in parallel relation, a sliding member in said passage, said sliding member having a plurality of contact pieces in spaced parallel relation at least at one side thereof adjacent the longitudinal edges of said sliding member, a plurality of longitudinally spaced spring contact means secured in said frame at least at one side of said passage and adapted to engage said contact pieces of said sliding member, a plurality of said spring contact means having integral soldering tags at each end projecting from said frame, a strip member interconnecting said soldering tags, and a leaf spring member adjacent said strip and substantially coextensive therewith, said spring contact means being secured in said frame aligned with one of said first and second apertures to provide access thereto for adjusting the spring tension of said leaf spring member.

4. A sliding switch according to claim 3 wherein said spring contacts secured in said fillets engage the contact pieces of said sliding member remote from the fillet in which the spring contacts are supported.

5. A sliding switch frame having a pair of spaced parallel rail portions and a plurality of spaced rod porv tions defining a longitudinal passage in said frame member for receiving a sliding member, each said rail portion having a longitudinal groove for guiding the sliding member within said passage, a plurality of elongated contact members extending through said passage and embedded in each of said rail portions, said contact members having soldering tags projecting beyond said rail portions and a resilient tongue portion struck from a part of said contact members and extending into said passage for engagement with the sliding member.

6. The combination according to claim 5 wherein each said guide rail is provided with a plurality of aligned apertures formed therein adjacent said contact members for removal of said contact members from said frame member.

7. An article of manufacture comprising a molded sliding switch frame, said frame having a pair of spaced parallel rail portions each having a plurality of aligned apertures therethrough, a plurality of spaced rod portions defining a longitudinal passage in said frame for receiving a contact bearing slide, each said rail portion having a longitudinal groove, a plurality of elongated contact members extending transversely through said frame and embedded in each said rail portion, a pair of soldering tags at each end of said contact members projecting from said frame, and each said contact member having a resilient tongue portion struck therefrom and partly projecting into said longitudinal passage and a conducting strip in said frame interconnecting said soldering tags.

References Cited in the file of this patent UNITED STATES PATENTS 1,123,758 Knoblock Jan. 5, 1915 1,739,889 Conti Dec.'17, 1929 2,135,435 .Zwack Nov. 1, 1938 2,671,137 Zaug -Q Mar. 2, 1954 2,672,531 Stevenson Mar. 16, 1954 3,023,287 Epstein Feb. 27, 1962 FOREIGN PATENTS 661,520 France Mar. 5, 1929 

1. IN A SLIDING SWITCH THE COMBINATION COMPRISING AN OPEN FRAME MEMBER HAVING SPACED PARALLEL LONGITUDINAL FILLET MEANS DEFINING A PLURALITY OF FIRST OPENINGS IN SAID FRAME IN A FIRST PLANE NORMAL TO THE LONGITUDINAL AXIS OF SAID SWITCH, A PLURALITY OF SPACED PARALLEL ROD MEANS INTERCONNECTING AND SUPPORTING SAID FILLETS AND DEFINING A PLURALITY OF SECOND OPENINGS IN SAID FRAME NORMAL TO THE LONGITUDINAL AXIS OF SAID SWITCH AND THE SAID FIRST OPENINGS, A CENTRAL LONGITUDINAL PASSAGE THROUGH SAID FRAME MEMBER, A SLIDING MEMBER IN SAID PASSAGE, SAID SLIDING MEMBER HAVING A PLURALITY OF CONTACT PIECES IN SPACED PARALLEL ROWS ADJACENT THE LONGITUDINAL EDGES OF SAID SLIDING MEMBER, AND A PLURALITY OF SPRING CONTACTS SECURED IN SAID FRAME, SAID SPRING CONTACTS COMPRISING A CONDUCTIVE PLATE HAVING A RESILIENT TONGUE PORTION AND SOLDERING TAGS AT THE LONGITUDINAL EXTREMITIES THEREOF PROJECTING BEYOND SAID FILLETS OF SAID FRAME, SAID SPRING CONTACTS BEING SECURED IN SAID FRAME FOR ACCESS THERETO THROUGH AT LEAST ONE OF SAID OPENINGS TO ADJUST THE TENSION OF SAID TONGUE PORTION. 